Movements in Meditation

Some years ago I learned Primordial Sound Meditation and attended a Seduction of Spirit week-long event. I have been meditating off and on since then, more off than on. This is because when I meditate (either primordial sound or some other type, for example as learned in a Jose Silva class) may hands (particularly my right hand) will rise on its own accord and being to rotate at the wrist. I have had other sensations as well – my head will rotate and feel pushed over either my right or left shoulder as far as it can stretch. Sometimes my head will rotate and perform what I can only describe as “stretching exercises.” These are not gentle movements – they are very strong and very powerful, although slow and almost methodical. I haven’t (yet) become alarmed by the movements, because they are not painful (the stretching is almost pleasant like yoga)  but they do seem to keep me from meditating regularly. Is this something I should avoid and it is helpful for me to resume my meditation practice? If I feel these sensations coming on, should I end my meditation immediately or somehow direct my mind to “talk my body out of” these movements? What is going on? Thank you.